Conventional ink cartridges employed in ink jet printers generally have the construction shown in FIG. 10. The ink cartridge 110 has an ink compartment 112 that maintains an ink supply and an adjacent filler compartment 116 that houses an absorbent filler 114. A partition 120 separates the ink compartment 112 and the filler compartment 116 and defines an opening 118. The opening 118 allows fluid communication between the ink compartment 112 and the filler compartment 116. The filler compartment 116 includes an ink expulsion opening 122 for discharge of ink to an ink jet head, a rib 124 that presses against the filler 114, and an air vent opening 126 to allow air to enter the ink cartridge 110. The rib 124 and the air vent opening 126 are formed in the top wall of the filler compartment 116.
For the ink cartridge 110, ink stored in the ink compartment 112 sufficiently penetrates the filler 114 via the connecting opening 118. When the ink cartridge 110 is mounted upon a carriage fitting (not shown), a connecting terminal (not shown), which protrudes from the carriage fitting, extends through the ink expulsion opening 122 and into the filler 114. When this occurs, the ink contained in the filler 114 flows into a carriage guide path (not shown) via holes in a tip of the connecting terminal (not shown), whereupon the ink is supplied to a coupled ink jet head.
While the ink cartridge 110 exhibits little ink leakage when operatively positioned relative to a carriage and stably expels ink quantities during operation, use of the ink cartridge 110 commonly results in wasteful consumption of ink and, consequently, the ink cartridge 110. Specifically, the ink cartridge 110 is typically replaced when the ink compartment 112 is depleted; however, in this condition, the filler 114 continues to maintain a significant quantity of ink. Thus, discarding the ink cartridge 110 in this state results in wasteful consumption of ink and the ink cartridge 110.
Accordingly, a need exists for an ink cartridge that fully utilizes ink stored in a filler after depletion of an ink supply within an ink compartment.